Daydream believer: Rats dream of a better future
It seems humans are not alone when it comes to dreaming of a better life for themselves: apparently, rats do it, too.聽
When at rest, rats and mice conduct mental rehearsals of journeys toward a desired future, such as a tasty treat, researchers at University College London (UCL) have found. The new , which compared rats鈥� brain activity while the animals were in various stages of motion and rest, could help explain why some people with damage to the hippocampus 鈥� the part of the brain thought to be responsible for memory and spatial recognition 鈥� struggle to imagine the future.
It could also provide insight into what goes on in the human mind during sleep.
鈥淒uring exploration, mammals rapidly form a map of the environment in their hippocampus,鈥� Dr. Hugo Spiers, the study鈥檚 senior author, research news site Science Daily. 鈥淒uring sleep or rest, the hippocampus replays journeys through this map which may help strengthen the memory.鈥�
The researchers used electrodes to monitor the animals鈥� brain activity in three different situations: first, as the rats were shown food they couldn鈥檛 access, then as they rested in a separate area, and lastly, as they walked to the food. They found that brain cells involved in navigation showed similar activity when the rats were resting and when they were walking to and from the food, indicating that the brain was simulating or preparing future paths leading to a desired goal.
The process took up about 8 percent of the rats鈥� brain activity during sleep. While that may not sound like much, it鈥檚 still a lot of energy to give a single task during rest, Dr. Spiers Discover magazine.
The results support the idea that sleeping improves performance on certain memory tasks, particularly those tied to a specific desire, the magazine reported.
鈥淧eople are much better at doing the stuff that they鈥檒l make more money on after they鈥檝e slept,鈥� Spiers said. 鈥淪omething about sleep is using that desire information: that you do want to do better.鈥�
The study stopped short of conclusively finding that rats dream these mental replays 鈥� 鈥淵ou can鈥檛 ask rats what they鈥檙e thinking or dreaming,鈥� Spiers told Discover 鈥� but it does suggest that the ability to imagine future events is not unique to humans.
鈥淲hat's really interesting is that the hippocampus is normally thought of as being important for memory, with place cells storing details about locations you鈥檝e visited,鈥� the study鈥檚 co-lead author, Dr. Freyja 脫lafsd贸ttir, told Science Daily. 鈥淲hat鈥檚 surprising here is that we see the hippocampus planning for the future, actually rehearsing totally novel journeys that the animals need to take in order to reach the food.鈥�
